This invention relates to an improved process for desulfurization of a waste gas containing sulfur dioxide. More particularly, it relates to a process for removing sulfur dioxide from a flue gas using a solid phosphorus-promoted sodium vanadate adsorbent.
Sulfur dioxide is known to be an undesirable atmospheric pollutant. It is known in the process art to adsorb sulfur dioxide from a waste gas by contacting the gas with a solid adsorbent, such as a porous alumina carrier having disposed thereon alkali metal oxide and vanadium oxide components (that is, alkali metal salts of oxyacids of vanadium) (see for example, representative U.S. Pat. Nos. 3,501,897 and 3,816,597). However, such adsorbents are not ideal, since their adsorption capacities are just moderate. Accordingly, there is a need for a means to enhance the sulfur dioxide capacity of such adsorbents.
My copending application Ser. No. 919,207, filed on June 26, 1978, my U.S. Pat. No. 4,239,742 issued Dec. 16, 1980, discloses a method for forming concentrated hydrogen sulfide from dilute sulfur dioxide in gases by adsorbing the sulfur dioxide with an adsorbent containing sodium, vanadium and alumina, converting the sulfur to sulfide form with carbon monoxide, and forming hydrogen sulfide by contacting the adsorbent with steam. The disclosure of Ser. No. 919,207 is incorporated herein by specific reference.